Though Linux continues to gain steam as an operating system for mobile phones, Symbian remains a dominant mobile OS.

Thanks to a new effort from cell phone giant Nokia , the divide between applications targeted at Linux and those for Symbian may be getting a whole lot narrower.

The Nokia Open C Plug-In extension for the S60 3rd Edition Software Development Kit (SDK) is designed to help the community of open source applications and developers take their apps and port them to Symbian. Nokia's S60 platform is built on top of the Symbian OS.

Open C is a set of POSIX and middleware C libraries that increases the speed of application development by enabling the use of existing software.

The Nokia effort is built on the Symbian PIPS effort, which was formally announced at the beginning of this year. PIPS is a recursive acronym for PIPS Is POSIX on Symbian. PIPS is geared to provide POSIX API compatibility with Symbian OS devices.

While Linux is defined to be a POSIX compliant operating system, Linux developers need to typically go beyond just basic POSIX compatibility and that's where Nokia's Open C comes in.

"Why did we develop Open C?" Nokia spokesperson Ravi Belwal said. "We don't want to reinvent the wheel. We don't want developers to have to do any extra work in porting their applications."

Open C Plug-In includes the core functions from the mobile libraries of the main open source desktop and server projects. Nokia claims that their plug-in includes 100 percent coverage of libraries for mobile critical functions such as password hashing, compression and loading DLLs.

"It is not easy to start developing on an S60 and there is a learning curve involved," Belwal said. "With Open C we have reduced that learning curve, meaning anyone that already has some open source component or application they can easily port to Symbian without having to learn a lot about Symbian the only thing they should understand is C and C++."

Surprisingly though, Nokia has elected to support the GNOME desktop library rather than the Qt library used by many mobile Linux efforts, including those of rival Motorola. Qt, developed by Trolltech, has a mobile offering called Qtopia, whichsits at the core of Motorola's Linux offering.

Trolltech declined to comment directly on whether or not they have been in negotiations with Nokia for the use of Qtopia.

"The recent move by Nokia to more meaningfully engage in the open source community and provide a path for mobile developers is a good one," Trolltech CTO Benoit Schillings said in a statement sent to internetnews.com. "Open source and open phones are the key to unlocking the next wave of innovation on handsets."

Beyond the potential Qt-versus-GNOME issue, open source developers might face, there may also be an issue around performance with Open C.

"When you are developing anything in native Symbian OS, definitely it will be faster than anything that is developed in Open C," Belwal admitted. "There are performance issues, but as an end user you won't be able to notice any delays. If you are a developer, maybe you will."